1. Technical Field
This invention relates generally to telecommunication instruments having a microphone mounted in a flip assembly and more particularly to such an instrument in which the electrical connection between the flip-mounted microphone and the instrument body is provided by a slip ring connection.
2. History of Related Art
Microphones that are mounted in the flip cover of portable telecommunication instruments generally have a high failure rate. Flip cover-mounted microphones are easily damaged as a result of impact shock, flexing of the electrical leads between the microphone and the main body of the instrument, and as a result of the "fidget factor", i.e., the natural human tendency to actuate a dynamic or moveable mechanism. Replacement of a microphone mounted in a flip assembly typically requires disassembly of the instrument requiring the services of a skilled technician at an authorized repair depot.
Typically, a microphone mounted in the flip cover of a telecommunication instrument is hard wired to a printed circuit board positioned within the main housing of the instrument. Consequently, the wires or flexible cable interconnecting the microphone with the instrument circuitry is soldered at one end to the microphone mounted in a relatively heavy flip cover assembly, and soldered at the other end to contacts provided on a correspondingly relatively heavy printed circuit board. Thus, the soldered electrical connections to each member are prone to being pulled lose from the respective connecting structure during movement of the flip member. Furthermore, wires and/or flex strips often cannot meet the cycle requirements found in a flip environment.
Heretofore, microphones mounted in flip covers have had three major shortcomings. The first problem arises from the unreliability of the dynamic hinge between the flip cover and the main housing of the instrument which flexes in a bending mode and is thereby prone to premature failure. Another problem with hardwired microphones mounted in the flip cover of a telecommunication instrument is attributable to manufacturing difficulties. Intense hand assembly is required to thread the microphone wires or flex strips through the flip hinge into the transceiver housing and make the subsequent soldered connection to the printed circuit board. In order to assemble, three major components of the instrument must be handled simultaneously; the printed circuit board, the flip cover and the housing. This virtually eliminates any opportunity for automation of the assembly process. Thirdly, when hard-wired flip-mounted microphones lose connection to the printed circuit board during operation, repair of the connection presents a serious problem. The instrument must be taken apart, the flip assembly removed and replaced, the interconnection to the printed circuit board repaired, and the instrument submitted to compliance testing to ensure proper operation. Since the instrument was opened up, full electrical verification, e.g., the restoration of proper electromagnetic interference (EMI) shielding must be verified before the instrument is returned to service.
The present invention is directed to overcoming the problems set forth above. It is desirable to have a microphone mounted in a flip arm that can be advantageously positioned close to the mouth of a user, and folded to a stored position when not in use. It is also desirable to have such a microphone mounted in a flip arm that is removably attached to the instrument whereby the flip arm and microphone assembly can be easily replaced if either the flip arm, microphone, or electrical interconnection of the microphone to the instrument circuitry, become damaged. It is also desirable to have such a microphone mounted in a flip arm of a telecommunication instrument that does not require direct-soldered connections to internal circuits of the instrument.